The present invention is directed to a retractable reel assembly having a channeled ratchet mechanism and a multi-compartmented housing.
Retractable reels have been used in various applications to retractably store various types of cables. For example, a conventional retractable reel assembly for use with a telephone cable has a reel on which a length of a round telephone cable is retractably wound. The telephone cable has an outer insulating jacket and a plurality of internal conductive members, each of which is composed of a wire jacketed by an insulating cover. A helically coiled spring urges the reel to rotate in a direction to cause the round telephone cable to be retracted back into the reel after it is pulled out. The reel has an expansion chamber in which a flat cable is spirally disposed. The flat cable in the expansion chamber is connected to the round cable on the reel via a pair of connectors disposed within the reel.
Examples of such retractable reels may be found in U.S. Pat. Nos:
______________________________________ 1,276,825 2,979,576 1,446,410 3,061,234 1,737,978 3,584,157 1,865,069 3,657,491 1,958,626 4,053,118 2,206,352 4,062,608 2,211,561 4,384,688 2,262,587 4,472,010 2,678,779 4,646,987 5,094,396 ______________________________________
A retractable reel is usually provided with some type of ratchet mechanism for controlling the retraction of the cable into the reel. For example, U.S. Pat. No. 5,094,396 to Paul Burke discloses a retractable reel assembly for a telephone extension cord having a ratchet comprising a ratchet gear, a pawl lever and a spring. U.S. Pat. No. 4,384,688 to Smith discloses a reel for storing a retractable cord having a ratchet gear that selectively engages a pawl that is biased by a spring about a pivot point.
A disadvantage of such prior retractable reels is that the helically coiled springs used to rotate the reel in the direction causing retraction of the cable are expensive to manufacture and difficult to assemble to the other components of the cord reel, all of which adds cost and complexity to the retractable reel. Also, the helically coiled springs wind during manual extension of the telephone cord and unwind when urging the reel to rotate in the direction retracting the cord. As the cord winds onto the reel, its diameter on the reel increases, resulting in i decreasing retraction force to be exerted on the cord for a given rotational torque exerted by the spring on the reel. Disadvantageously, as the helical spring unwinds the rotational torque it exerts on the reel decreases, resulting in a rapidly decreasing retraction force being exerted on the cord and a potential failure of the cord to be retracted under various conditions. One way to overcome a decreasing rotational torque exerted by a helical spring as it unwinds is to use a constant force spring to urge the reel in the direction of rotation causing retraction of the spring, for example a constant force spring of a type disclosed in U.S. Pat. No. 5,124,685. In that patent, a retractable tether using a constant force spring serves as a security device for merchandise displayed for customer handling and demonstration.
Another disadvantage of prior retractable reels resides in the ratchet mechanism that is provided to selectively prevent retraction of the telephone cord. One such ratchet mechanism is disclosed in U.S. Pat. No. 5,094,396, issued to the present inventor and the teachings of which are incorporated herein by reference. In said patent the ratchet mechanism comprises, as is conventional, a ratchet gear, a pawl lever and a pawl spring for urging the pawl lever into engagement with the ratchet gear. A particular disadvantage of such conventional ratchet mechanism is that the required spring adds cost and complexity to the retractable reel, both because of the cost of the pawl spring itself and because of the increased cost incurred as a result of the additional time and complexity occasioned in assembly of the retractable reel as a result of the spring.
Also known in the art are reels that embody a ratchet mechanism that does not utilize a pawl spring. Instead, the ratchet mechanism comprises a circular ratchet plate having arcuate channels formed in a surface thereof and a pawl that is pivotally supported at one end and has a follower at an opposite end that rides in and is guided by the channels in response to relative rotation between the pawl and ratchet plate. The resulting ratchet mechanism is an improvement over the spring loaded type ratchet mechanisms previously encountered. However, these reels are difficult to assemble, since the ratchet plate is formed in a surface of a stationary housing for the retractable reel while the pawl is carried by and rotated with a spool of the assembly.